The open windows beta started about a month ago, and I'm happy to report we may in fact have a winner. I made a detailed list of all the features I use in photoshop, and ended up with a list of 111 features. Affinity covers 101 of those features. Plus, it has a bunch of new features I've wanted for a long time, like an improved Liquify, more no destructive procedural filters, brush categories, multiple layer masks. In fact, the only must have feature it lacks for my workflow is the ability to clip layers to groups.
The future in painting/photomanip apps finally looks bright again, and it looks like we will indeed have a viable alternative in the near future. Check out the open beta and support this software!